Files with VSDM extension are drawing files created with Microsoft Visio application that supports macros. VSDM files are OPC/XML drawings that are similar to VSDX but also provide the capability to run macros when the file is opened. Macros are user-defined actions/steps that are developed in Visual Basic for Applications (VBA) and can be used to perform repetitive tasks.
You can also add watermark to many other file formats. Please see the complete list below.